soszip2 - brute-force comression utility

[kappa]

can’t extract the zip file here on linux

skipping: soszip2.exe             need PK compat. v6.3 (can do v2.1)

edit: nvm, works with 7z not unzip

[kappa]

@kapta

Sos just curious, can your tool be used generically just to produce small .lzma files (non 4k and zip stuff) ?

k, guess not, it only supports a single file and not a bunch of files or existing zip file. Also produces zip and not lzma.

[Sos]

I updated the tool with small batch file that uses pack200 to strip some data from the package. I hope this will give it some boost. The link remains in the first post.
Type sospack for usage info.

[pjt33]

@Riven

You can simply strip data off of a zip and end up with a GZ.

You have to stick a gz header on too.

[Groboclown]

@Riven

@Groboclown

One thing to note about the LZMA compression is that it will only work for Jar files. There’s a method that some of us use for converting a zip compressed file into a gz file (for pack200 compression), and the gzip format (from what I’ve seen) doesn’t support LZMA.

Zip = multiple entries of GZ

If a compression works in ZIP, it works in GZ.

In my compile-and-shrink service, I use 7z (which is LZMA) too for GZ files.

Perhaps I’m doing something wrong, or I’m misunderstanding something, but I just attempted to use the LZMA method in 7z to construct a jar (and, thus, also the gz file which has a stripped header):

> 7z a -bd -tzip -mx=9 -mm=LZMA -mtc=off -mcl=on -mcu=off test.jar D.class

I attempted to use the resulting jar file in Chrome, and the JVM fails with “Cannot load class D”. Using the Deflate method instead doesn’t cause this error.

[Riven]

As said, the JVM doesn’t support the LZMA algorithm, hence I removed it from compile-and-shrink.

[Groboclown]

@Riven

As said, the JVM doesn’t support the LZMA algorithm, hence I removed it from compile-and-shrink.

Ah, I overlooked that. Thanks.